Generally when medicinal substances such as physiologically active agents are administered into the body through oral administration applied as a general method for applying medicine, administering the medicinal substances is impossible because the medicinal substances are likely to undergo metabolic changes in the liver after being absorbed and the absorbability of the medicine is generally poor. Therefore in spite of the fact that many medicines promise excellent medical effects, a convenient method utilizing medicines was not yet established and the method of administering medicines must be relied on an injection which is troublesome at a clinical site and gives pain to the patients. In these circumstances, a simple administrative technique which is also capable of avoiding the effects of initial passage of the medicine through the liver is desired. Methods which avoid effects of initial passage through the liver include administration through the skin, nose, rectum, lungs and oral mucous membranes. However each of these paths has physical limits for most medicines as to the amount of the medicine being absorbed to obtain a sufficient clinical effect. This served to demonstrate the need for methods for facilitating absorption.
In a search to resolve these problems, most attention in recent years has focused on iontophoresis as a method to effectively administer ionic medicinal substances into the body by absorption through the skin. Iontophoresis is a device which causes absorption of the medical substances to occur by means of an electrical current passed through the ionized medicinal substances. In the iontophoresis device, anode and cathode iontophoresis electrodes are sticked to the skin at regular intervals and an electrical current generated by a current generator is led through the wire leads between the iontophoresis electrodes. Many such iontophoresis devices have previously been employed (Japanese Patent Laid-Open No. 60-188176 and Japanese Patent Publication No. 4-74030). In these patents, the iontophoresis device is provided with a anode iontophoresis electrode containing the positively ionized medicinal substances or is provided with a cathode iontophoresis electrode containing the negatively ionized medicinal substances. A conductive layer filled with sodium chloride and the like is generally utilized for iontophoresis electrodes not containing a medicinal substances.